1. Field
This relates to a light emitting device.
2. Background
Generally, a light emitting diode (LED) as a light emitting device is a semiconductor device, which emits light in accordance with recombination of electrons and holes. Such an LED is widely used as a light source in optical communications, electronic appliances, etc.
The frequency (or wavelength) of light emitted from an LED is a function of the bandgap of a material used in the LED. When a semiconductor material having a narrow bandgap is used, photons of high energy and long wavelengths are generated. On the other hand, when a semiconductor material having a wide bandgap is used, photons of short wavelengths are generated.
For example, an AlGaInP material generates light of red wavelengths is generated. On the other hand, silicon carbide (SiC) and Group-III nitride-based semiconductor, in particular, GaN, generate light of blue or ultraviolet wavelengths.
Recently, light emitting devices are required to have high brightness so that they may be used as light sources for illumination. In order to achieve such high brightness, research into manufacture of a light emitting device capable of achieving uniform current diffusion, and thus, an enhancement in light emission efficiency, is being conducted.